The graphic co



`@einen tstrs @anni @fitta JULES GONVERS, OF PARIS, FRANCE.

' Letters Patent No. 82,805, dated October 6, 1868.

IMPROVEMENT IN MAKING (iRANK-SHAFT.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JULES Convenant No. 4 Rue de la Paix, Paris, in the Empire of France, chief engineer of the French and American-Transatlantic Company, have invented a new and improved Arrangement Applicable to the Main Shafts of Steam' and other Engines, giving to such shafts a much greater solidty, andconsiderably increasing their duration; and I do hereby declare that -the following is a. full, clear, and exact description thereof, reference being had to the accompanying drawings,and to the letters of reference'marked thereon. i

The main shafts of locomotive, marine, and other engines, the shafts of which are of the cranked description, and of which the wrists for the connecting-rods are forged together with the cranks, vmost frequently break ait the joining-line ofthe wrist with the crank-arms. i

The annexed drawing will convey to the mind the idea of my invention.

Figure lis a front view of aeranked shaft for the transatlantic steam-vessel Saint Laurent, of nine hundred-horse-power, drawn to a scale of one-tenth, in which the collar is shown lin section.

Figure 2 is a cross-section ofthe sameshaft, through the line XY.

When unsoundness of the` cranked partof a shaft begins to show, rounded angle which unites the wrist.A tothe arm B. This crack, which is at C, inside of the arm, theoil penetrates, and the shaft in a short timefb'ecomes unfit for work.

it is produced by a small crack in the widens,

This effect is produced because the fibres of the iron are forcibly cut off between the arms, when forging such shafts, and of course they are not dt to sustain rmly the violent shocks the shaft is supporting.

Instead of forging the wrists together with the arms of cranks, it was tried to introduce separate wrists in the eye of said arms, and fastening them tight by keying; but wrists so adjusted move after a while, and the centre going lno longer true, the engine cannot work well. i

The object of my invention is to obviate this serious inconvenience.

I forge the cranked shafts, as usual, in a single piece, centre of the wrist a hole which must be accurately true, and in such hole I introduce a central iron or ste'el wrist, D, 'which is prepared for this purpose, and the libres of which cannot have been cut off by the arms, as the outside wrist which surrounds it. l

This internal wrist or reinforce will have all the strength required to resist the clipping motion, and, owing to its envelope, it will have no tendency to shake away. v

To fit it in place, it can be cooled, and the socket-collar heated, or a hydraulic press may be usedto force itin.

The usual means will be used to secure it in positiona shoulder, E, .and either a screw-nut or keys, F.

The annexed drawing exhibits, as aforesaid, on a scale ofone-tenth, ashouldered internal wrist, inserted in the centre of the wrist, forged with the crank-arms of the main shaft of a nirie-hundred-horse-power engine, intended for the Steamship Saint Laurent, to ply between Brest and New York. The internal wrist may b either concentric or not with its 'casing or outer wrist. In either case it mustrbe calculated, as well as its casing and crank-arm, according to vthe force' it will have to resist.

The same arrangement may be 'likewise applied to the stoc lof the crank.

But it is chieflyfo'r the wrist of the cranked s even if a crack were to break out in the outside co stopped by the inside wrist, which runs no danger of strain or rupture,V movement which the shafts may have to sustain.

What I claim as niyiinvention, and desire to secure by Letters Patent, is 4 The improved method, herein described, of making crank-axles, by forging themiirst, as usually done, in one solid piece, then boring the shouldere pins, I), of Steel or other strong material, embraced e set forth.

k G of the shaft, at its junction with the armsB haft., that my improved system offers great advantages, for llar, it would not be very important, and would find itself and can stand any binding or twisting JuLEsconviens,

Rue de la Paix, 4, Pars.

Witnesses:

L. DAUBRVILLE, Boulevard de Strasbourg, 60.

J. GUIcNoT', Rueda la Paix, 4.

with wrists vand arms, and when finished, I'bore in the d parts thereof, and strengthening the same by introducing separateA ntirely within thc metal, as and for the purposesv herein 

